The Japanese call it pok-kuri. Filipinos call it bangungot or batibat. For the Hmong people of Vietnam and Laos, it is the tsob tsuang. Taiwanese men, some of whom wear lipstick to bed in order to deceive nocturnal ghosts, claim it is the phi am or a malevolent spirit who, much like Freddy Krueger, steals away the souls of young men in their sleep. All these names refer to the same thing: Nightmare Death Syndrome.